898 



Tlie observations contained in the scheme are tor a part inserted 

 in the graphic representation I. 



Ji/ffSO, 



\ucmxi salt (/n ?n.m/)t. — > 



V^ 



B. Com/)arison of the action of the chlorides of Mg, Ca, Si\ 

 Ba and of Zn, Cd and Hg. 



As the concentration of these salts is not to be fixed accnrately 

 by weighing, standard solnlions were made, the content of which 

 was estimated by the Volhard volumetric method. These solutions 

 were diluted to a content of 4 milliinol. per 160 ccm. (284 mg. of 

 chlorine). 



Hence each ccm. contains ^ j ^^ millimol. 



To the bath of 1 mgr. of benzopurpurin in ±0.5 litre of distilled 

 water were now added respectively 5 (7^ millimol.), 10 (74 'ïiiHiniol.), 

 15 (Vg inillimol.), 20 (7, niillimol.) and 40 (one millimol.) ccm. of the 

 different salt solutions and left in contact with 1 gram of cotton 

 during 10 minutes at 65° as mentioned above. 



Afterwards the exhausted baths were compared with the original 

 dyestuff solution and in this way their strength was determined; 

 by way of controlling the exhausted baths of different salts were 

 also mutually compared and no deviations of any importance were 

 ever observed. 



